A high speed bagging assembly typically seals bags by passing the upper portion of the open bag through a series of heating, compression, and cooling platens. The heating platens melt the bag, the bag liner or a sealing tape folded over the opening to create closure of the bag. The compression platen cooperating with compression rolls compress the upper portion of the bag to further ensure closure of the bag and the cooling platens cool the heated and compressed portion of the bag.
There are typically 3-13 pairs of platens in the bag sealer portion of a high speed bagging assembly. Each platen pair is arranged in a spaced apart, face-to-face orientation. The gap located between the facing platen pairs is the area through which the upper and open portion of the bag and sealing band are routed. The gap distance between the facing platens must be adjusted to correspond to the particular bag and sealing band thickness. Each platen pair consists of a stationary platen and an adjustable platen such that the gap size is adjusted by moving the adjustable platen towards or away from the stationary platen. In the prior art, the gap size was changed by manually rotating jack screws located on each adjustable platen for moving the platen to obtain the proper distance from the stationary platen. This manual procedure is time consuming and tedious. Each time the machine is changed over for a different bag type, each individual platen pair must be adjusted for the proper gap size. Attention must be paid to ensure that each separate platen pair has the correct gap size. If there are any variations in the gap size along the length of platens, a jam could result at an area that is too narrow and ineffective sealing could result where the gap is too wide. Furthermore, set up time is slowed and more maintenance is required on the individual platens.
An additional drawback of the need to separately adjust each individual platen pair is that if a jam occurs, the specific platen or platens involved in the jam must be individually moved out of operating position. Once the platens are out of operating position, the jam can be removed. However, after the jam is removed the individual platens must be carefully readjusted to the desired gap size.
Accordingly, what is needed is a mechanism to simultaneously adjust the platens in the bag sealing portion of a high speed bagging assembly to achieve the desired gap size along the length of the platens. The present invention addresses this problem by providing a single apparatus for simultaneously adjusting the platens to obtain the desired gap size between the series of platen pairs. Furthermore, it incorporates an air actuated cylinder for simultaneously increasing the gap size between the series of platen pairs taking them out of an operating position, allowing the operators to easily clear jams.
It is accordingly a principal object of the present invention to provide an improved apparatus and method for simultaneously adjusting the gap size between pairs of heating, compression, and cooling platens used in a bag sealer assembly of a high speed bagging assembly.
Another object of the present invention is to provide a platen adjust apparatus for simultaneously and uniformly moving a series of platens to obtain a desired gap size between the platen pairs along the entire length of the series of platen pairs of the bag sealer which allows faster set up time and easier changeover for different bag configurations.
Still another object of the present invention is to provide a platen adjust apparatus which allows a quick operator response to jams along the heating, compression, and cooling platens without either the need to change the platen gap size setting or the need to adjust each individual platen pair located in the jammed area.
Yet another object of the present invention is to provide a platen adjustment apparatus where the heating, compression, and cooling platen pairs are initially and individually calibrated when installed and then the operator is able to use a single adjustment to simultaneously adjust and readjust the platens to accommodate the desired bag thickness.